This chapter describes how to install Oracle Application Server in OracleAS Disaster Recovery configurations. OracleAS Disaster Recovery is one of the high availability environments supported by Oracle Application Server.

10.1 OracleAS Disaster Recovery: Introduction

Use the OracleAS Disaster Recovery environment when you want to have two physically separate sites in your environment. One site is the production site, and the other site is the standby site. The production site is active, while the standby site is passive; the standby site becomes active when the production site goes down.

OracleAS Disaster Recovery supports a number of basic topologies for the configuration of the Infrastructure and middle tier on production and standby sites. OracleAS Disaster Recovery supports these basic topologies:

Symmetrical topologies -- strict mirror of the production site with collocated Oracle Identity Management and OracleAS Metadata Repository Infrastructure

In a symmetric topology, each node in the standby site corresponds to a node in the production site. This includes the nodes running both OracleAS Infrastructure and middle tiers. In an asymmetric topology, the number of instances required on the standby site are fewer than the number on the production site and the number of instances required on the standby site must be the minimum set of instances required to run your site in the event of a switchover or failover operation.

For these supported topologies, OracleAS Guard will be installed in every Oracle home on every system that is part of your production and standby topology configured for the OracleAS Disaster Recovery solution.

For OracleAS Disaster Recovery to work, data between the production and standby sites must be synchronized so that failover can happen very quickly. Configuration changes done at the production site must be synchronized with the standby site.

You need to synchronize two types of data. The synchronization method depends on the type of data:

Use Oracle Data Guard to synchronize data in the OracleAS Metadata Repository databases on the production and standby sites. You can configure Oracle Data Guard to perform the synchronization.

Use the backup and recovery scripts to synchronize data outside of the database (such as data stored in configuration files).

See the Oracle Application Server High Availability Guide for details on how to use Oracle Data Guard and the backup and recovery scripts.

10.2.1 Ensure Nodes Are Identical at the Operating System Level

Ensure that the nodes are identical with respect to the following items:

The nodes are running the same version of the operating system.

The nodes have the same operating system patches and packages.

You can install Oracle Application Server in the same directory path on all nodes.

10.2.2 Set Up staticports.ini File

The same component must use the same port number on the production and standby sites. For example, if Oracle HTTP Server is using port 80 on the production site, it must also use port 80 on the standby site. To ensure this is the case, create a staticports.ini file for use during installation. This file enables you to specify port numbers for each component. See Section 2.5.3, "Using Custom Port Numbers (the "Static Ports" Feature)" for details.

10.2.3 Set Up Identical Hostnames on Both Production and Standby Sites

The names of the corresponding nodes on the production and standby sites must be identical, so that when you synchronize data between the sites, you do not have to edit the data to fix the hostnames.

For the Infrastructure Nodes

For the node running the infrastructure, set up a virtual name. To do this, specify an alias for the node in the /etc/hosts file.

For example, on the infrastructure node on the production site, the following line in the hosts file sets the alias to asinfra:

138.1.2.111 prodinfra asinfra

On the standby site, the following line sets the node's alias to asinfra.

213.2.2.110 standbyinfra asinfra

When you install OracleAS Infrastructure on the production and standby sites, you specify this alias (asinfra) in the Specify Virtual Hostname screen. The configuration data will then contain this alias for the infrastructure nodes.

For the Middle-Tier Nodes

For the nodes running the middle tiers, you cannot set up aliases like you did for the infrastructure nodes because the installer does not display the Specify Virtual Hostname screen for middle-tier installations. When installing middle tiers, the installer determines the hostname automatically by calling the gethostname() function. You want to be sure that for each middle-tier node on the production site, the corresponding node on the standby site returns the same hostname.

To do this, set up a local, or internal, hostname, which could be different from the public, or external, hostname. You can change the names of the nodes on the standby site to match the names of the corresponding nodes on the production site, or you can change the names of the nodes on both production and standby sites to be the same. This depends on other applications that you might be running on the nodes, and whether changing the node name will affect those applications.

Verifying that the Nodes Resolve the Hostnames Correctly

After making the changes and restarting the nodes, check that the nodes resolve the hostnames properly by running the following commands:

10.2.4 If You Want to Use OracleAS Cold Failover Cluster on the Production Site

To set up OracleAS Cold Failover Cluster in this environment, use the virtual IP address (instead of the physical IP address) for asinfra.asha on the production site. The following example assumes 138.1.2.120 is the virtual IP address.

asmid1.asha IN A 138.1.2.333
asmid2.asha IN A 138.1.2.444
asinfra.asha IN A 138.1.2.120 this is a virtual IP address
remote_infra.asha IN A 213.2.2.110

On the standby site, you still use the physical IP address for asinfra.asha, but the remote_infra.asha uses the virtual IP address.

asmid1.asha IN A 213.2.2.330
asmid2.asha IN A 213.2.2.331
asinfra.asha IN A 213.2.2.110 physical IP address
remote_infra.asha IN A 138.1.2.120 virtual IP address

10.3.2 Installing Middle Tiers

You can install any type of middle tier that is compatible with Oracle Application Server 10g (10.1.4.0.1). See the Oracle Application Server Upgrade and Compatibility Guide for more information.

To install a middle tier, see the Oracle Application Server Installation Guide for the release.

Note the following points:

When the installer prompts you to register with Oracle Internet Directory, and asks you for the Oracle Internet Directory hostname, enter the alias of the node running OracleAS Infrastructure (for example, asinfra.oracle.com).

OracleAS 10g (10.1.2.0.2) standalone install of OracleAS Guard is located on Companion CD Disk 2. This standalone install of OracleAS Guard can be installed in the following environments:

In its own home in the case when you are cloning an instance or topology to a new standby system (see the section on standby site cloning in Oracle Application Server High Availability Guide for more information).

OracleAS Disaster Recovery full site upgrade from OracleAS 10g (9.0.4) to OracleAS 10g (10.1.2.0.2) (see the chapter on OracleAS Disaster Recovery site upgrade procedure in Oracle Application Server High Availability Guide for more information).

If this is an upgrade installation of OracleAS Guard, make a copy of your dsa.conf configuration file to save your current settings for your OracleAS Guard environment. After running the OracleAS 10g (10.1.2.0.2) standalone install kit of OracleAS Guard, you can restore your saved dsa.conf configuration file with your settings to continue using the same settings for the upgraded OracleAS Guard environment.

To run the OracleAS 10g (10.1.2.0.2) standalone install kit of OracleAS Guard, run the kit in the following directory path:

On UNIX systems:

/Disk2/asg/install/runInstaller

Choose the type of install that you want. Choose Typical for most installations. Choose Custom or Reinstall for upgrading from an older release of OracleAS Guard to the current release.

If you already have an OracleAS Disaster Recovery environment set up using OracleAS Guard Release 10.1.2.0.0, you can patch OracleAS Guard in your environment to take advantage of new features and support for the topologies described in Section 10.1, "OracleAS Disaster Recovery: Introduction". To patch your OracleAS Disaster Recovery environment, follow these basic steps:

Install the OracleAS 10g (10.1.2.0.2) standalone install of OracleAS Guard into each Oracle home on the production and standby sites.

If multiple Oracle homes exist on the same system, ensure that different ports are configured for each of the OracleAS Guard servers in this configuration file.

Because this is an upgrade installation of OracleAS Guard, make a copy of your dsa.conf configuration file to save your current settings for your OracleAS Guard environment. After running the OracleAS 10g (10.1.2.0.2) standalone install kit of OracleAS Guard, you can restore your saved dsa.conf configuration file with your settings to continue using the same settings for the upgraded OracleAS Guard environment.

On UNIX systems:

<ORACLE_HOME>/dsa/dsa.conf

Start the OracleAS Guard server in all OracleAS 10.1.2.0.0 Oracle homes on both production and standby sites using the following opmnctl command:

10.6 What to Read Next

For information on how to manage your OracleAS Disaster Recovery environment, such as setting up Oracle Data Guard and configuring the OracleAS Metadata Repository database, see the Oracle Application Server High Availability Guide.